EXHIBIT S
Radio and TV Analysis
APPLICATION TO THE OHIO POWER SITING BOARD FOR A
CERTIFICATE OF ENVIRONMENTAL COMPATIBILITY AND PUBLIC NEED FOR THE
GRANGE SOLAR GRAZING CENTER
Case No. 24-0801-EL -BGN
Grange Solar, LLC
Logan County, Ohio
Communication Systems (AM/FM Radio, TV, LMR, and Communications Towers) Interference Analysis
September 27, 2024
Introduction
Capitol Airspace conducted a communication systems interference analysis for the Grange Solar Grazing Center in Logan County, Ohio. At the time of this analysis, the solar array shown in Figure 1 had been identified The purpose of this analysis was to identify Amplitude Modulation (AM) and Frequency Modulation (FM) Radio, Television (TV), Land Mobile Radio (LMR) systems, and other communications towers that could be affected by the proposed solar array.
AM and FM radio, along with TV stations, are a critical component of the national communications infrastructure. These stations broadcast emergency, news, music, entertainment, and educational content. LMR systems play a critical role in enabling seamless communication among public safety agencies, emergency responders, and transportation services, ensuring swift and coordinated responses to urgent situations and enhancing overall public safety nationwide. Proposed structures that interfere with these systems can degrade the services that they provide.
Solar arrays have the potential to disrupt communication systems through several mechanisms: physical interference with the transmitted signal, as well as electromagnetic interference (EMI) and reflective interference to the receiving equipment The likelihood of disruption depends on the characteristics of the radio frequency (RF) signal and the proximity of the solar array components to communication system components. Therefore, the proximity of a solar array to a communication facility plays a crucial role in predicting potential interference. This analysis focuses on understanding how the placement of solar arrays relates to the probability of interference.
Methodology
Capitol Airspace studied the Grange Solar Grazing Center based upon location information provided by Grange Solar, LLC. Using this information, Capitol Airspace used a Geographic Information System (GIS) to determine proximity to communication facilities contained in the Federal Communication Commission (FCC) Universal Licensing System (ULS), Licensing and Management System (LMS), and Antenna Structure Registration (ASR)
This analysis considers the potential impact of the proposed solar project on communication system transmission facilities based on RF signal propagation characteristics, and on RF reception based on Electromagnetic Interference (EMI, or “RF Noise”) from the solar array components and physical reflections from the solar panels themselves.
AM Radio
Proposed structures located up to ten wavelengths from the transmitter can have an impact on the station. This is based on guidance provided by the FCC via 47 CFR §1.30002
FM Radio and TV
The location of a proposed structure within an RF signal’s propagation regions can determine the potential for impact (Figure 2). Within the near field, RF signals behave unpredictably and are more susceptible to distortion from obstacles. In the far field, radio waves are more parallel and uniform and have spread over a larger area. Obstacles in the far field are less likely to have an impact on RF transmission. The distance between the antenna and the beginning of the far field is called the “Fraunhofer distance ”
Figure 2: RF signal transition from the near-field to the far-field of a transmitter
LMR
The impact from proposed structures like solar arrays is primarily associated with the potential for EMI. As unintentional radiators, solar arrays have the potential to create EMI in proximity to LMR transmitters. The distance at which EMI may be a concern is based on guidance provided by the FCC via 47 CFR Part 15.
In many cases, ULS and LMS antenna locations as well as antenna structure registration (ASR) tower locations are inaccurate. When a communication system transmitter’s location was critical, available satellite and aerial imagery were used to improve its coordinates Available imagery was also used to identify potential receivers in proximity to the defined study area.
In addition to the effects of nearby solar arrays on transmission, the effects of EMI emitted from a solar project and reflections from the solar panels themselves on transmission systems reception was also studied.
Findings
Effects on AM Radio Transmission
Solar arrays located within six kilometers (km) of a transmitting AM facility (dashed purple outline, Figure 3) have the potential to adversely affect AM transmissions.1 This interference could cause the transmitting entity to be out of compliance with their FCC license. No transmitting AM facilities are located within six km of the study area (Table 1 and Figure 3). As a result, the proposed solar array should not create an adverse effect on the transmission of AM radio signals. The closest AM station to the project is WBLL(AM), which is 12.4 km from the nearest proposed PV array.
1 Six km is a conservative screening distance derived by rounding the worst-case FCC distance of 5.45 km derived from the FCC Rule Section 1.30002(b) directional AM radio station separation criteria, which is based on the distance of ten wavelengths at the lowest possible frequency, 550 kHz. Further, per this same Rule Section, the lowest structure height that may have a potential impact on an AM station within the screening distance is 178.8 feet at 550 kHz, which is well above the proposed height of any proposed solar array structure.
Effects of Localized EMI on AM Radio Reception
Due to its lower operating frequency range, AM Radio reception is by far the most susceptible to local EMI interference of all of the radio services. The proposed solar project should not interfere with AM radio reception from an EMI standpoint, as the proposed PV arrays are far enough away from potential AM receivers so as to not have an effect on AM reception. Based on client documentation, the minimum distance between an inverter and the nearest home will be 500 feet, the minimum distance between any solar panel and a public road will be 150 feet, and the minimum distance between any solar panel and a home that is not owned by a participant in the project will be 300 feet. However, should there be a complaint, a list of the 22 AM stations that serve the area is provided in Table 2.
There are 22 AM radio stations with signals that serve the area2 in which the Grange Solar Grazing Center is being built (Table 2 and Figure 4). Some of the AM stations listed are not authorized to operate at night.
Licensee Call Sign Status
Delmar Communications, Inc. WDLR(AM)
V-Tek Communications, Inc.
L&D Broadcasters Inc. WGNZ(AM)
Alpha Media Licensee LLC
St. Gabriel Radio, Inc.
Woof Boom Radio of Lima LLC
Blanchard River Broadcasting Company
Salem Media of Ohio, Inc.
IHM Licenses, LLC
Family Worship Center Church, Inc.
North American Broadcasting Company, Inc.
Pathfinder Communications Corporation
IHM Licenses, LLC
IHM Licenses, LLC
IHM Licenses, LLC
Radio Maria, Inc.
IHM Licenses, LLC
CMG Radio Operating Company, LLC
IHM Licenses, LLC
Muzzy Broadcasting, LLC
IHM Licenses, LLC
Radio License Holdings LLC
2 For this case, the rural 0.5 mV/m contour is used.
WING(AM)
WVSG(AM)
WCIT(AM)
WFIN(AM)
- Day
- Day
- Day
- Day
WRFD(AM) License - Day
WMRN(AM) License - Day
WJYM(AM) License - Day
WMNI(AM) License - Day
WOWO(AM) License - Day
WTVN(AM) License - Day
WIZE(AM) License - Day
WIMA(AM) License - Day
WULM(AM) License - Day
WKRC(AM) License - Day
WHIO(AM) License - Day
WONE(AM) License - Day
WPTW(AM) License - Day
WLW(AM) License - Day
WJR(AM) License - Day
4: AM stations serving the area within the Grange Solar Grazing Center boundaries
AM radio reception can be impacted by signals being intentionally or unintentionally emitted by electrical devices and appliances. In the past, some subsystems used in residential solar arrays were found to cause localized interference to AM radio reception. Properly designed, installed, and maintained industrial/commercial solar arrays have not been typically found to create localized EMI issues. While it is understood that the solar array is not an intentional RF radiator, it may be possible that some of the components, including system interconnection wiring and DC to AC inverters (the inverters in particular), can become “unintentional radiators.” Digital devices are classified as unintentional radiators that use digital techniques. Section 15.103(b) of the FCC rules provides exemptions for some types of digital devices:
“Except as provided in paragraph (j) of this section, the following devices are subject only to the general conditions of operation in FCC Rules Part 15.5 and 15.29, and are exempt from the specific technical standards and other requirements contained in this part. The operator of the exempted device shall be required to stop operating the device upon a finding by the Commission or its representative that the device is causing harmful interference. Operation shall not resume until the condition causing the harmful interference has been corrected. Although not mandatory, it is strongly recommended that the manufacturer of an exempted device endeavor to have the device meet the specific technical standards in this part” of the FCC rules
(a) A digital device utilized exclusively in any transportation vehicle including motor vehicles and aircraft.
(b) A digital device used exclusively as an electronic control or power system utilized by a public utility or in an industrial plant. The term public utility includes equipment only to the
extent that it is in a dedicated building or large room owned or leased by the utility and does not extend to equipment installed in a subscriber's facility.”
From the International Electrotechnical Commission’s (IEC) standards document IEC 61000-6, the distance required from the photovoltaic array electronics for unimpaired AM reception for this analysis is 30 meters (100 feet) 3 Based on client documentation, the minimum distance between an inverter and the nearest home will be 500 feet, the minimum distance between any solar panel and a public road will be 150 feet, and the minimum distance between any solar panel and a home that is not owned by a participant in the project will be 300 feet.
As a result, there should be no EMI “noise” effects on AM radio reception from inverters, control systems, or interconnecting wiring that are in compliance with the appropriate IEEE, IEC, and UL codes. Any possible effects are expected to be minimal and can be further mitigated if needed.
Effects of Localized Reflection on AM Radio Reception
As mentioned above, local reception of AM Radio stations is normally analyzed based on ground conductivity and “ground wave” propagation. The impact of reflections or blockage at AM frequencies near the solar array should be minimal due to the long wavelength of AM stations and low height of the PV array.
3 Up to 43V/m is acceptable @ 550KHz at distance of 30 meters. IEC 61000-6-4:2018 © IEC 2018
Effects on FM Transmission
Solar arrays located within one kilometer of a transmitting FM facility (dashed green outline, Figure 5) have the potential to adversely affect FM transmissions.4 There are no transmitting FM facilities located within one kilometer of the study area (Table 3 and Figure 5). As a result, the proposed solar array should not create an adverse effect on the transmission of FM radio signals. The nearest FM station to the project is Low Power FM station WRPO-LP, which is 1.3 km from the nearest PV array in the project.
Further, the possibility of a solar array interacting near-field effects on an FM transmission is extremely remote since FM transmitting antennas are typically elevated high above the terrain for maximum coverage It is improbable that a ground-based solar array would be within the main lobe pattern of a high-gain FM transmitting antenna in a way that interacts with the radiated pattern.
Therefore, the Grange Solar Grazing Center will have no near field impact to the operating characteristics of existing or proposed FM transmission facilities.
4 One kilometer is a conservative screening distance derived by rounding the Fraunhofer distance of 941 meters. The calculated distance of 941 meters is based on the largest typical off-the-shelf 12-element antenna and the lowest possible frequency of 88 MHz.
5
Effects of Localized EMI on FM Radio Reception
As an example of the minimal impact of such installations to the VHF FM band, in the past ten years, more and more airports have allowed photovoltaic (PV) projects to collocate on airport grounds. A number of government agencies, including the Department of Defense (DoD) and the Federal Aviation Administration (FAA), are concerned with potential interference for safety reasons, as there are a number of frequencies used at airports which are extremely important to airspace navigation that are very close to the FM radio frequency band (the FAA’s ILS localizer frequencies are directly above the FM band).
According to the Renewable Energy Program Office of the DoD,
“The Federal Aviation Administration (FAA) has indicated that EMI from PV installations is usually low risk. PV systems equipment such as step-up transformers and electrical cables are not sources of electromagnetic interference at frequencies above 108 MHz because of their low frequency (60 Hz) of operation and PV panels themselves do not emit EMI. The only components of a PV array that may be capable of emitting EMI are the system interconnection wiring and DC to AC inverters, which convert the solar panel’s low-voltage DC power into a higher voltage AC that can be carried efficiently for longer distances to the solar project’s electrical substation. Inverters may produce low frequency EMI similar to electrical appliances and at a distance of 150 feet from the inverters the EM field is at or below background levels.”5
Examination of the project documentation and aerial imagery indicates that there are no inverters within 500 feet of any residential structures, and 150 feet from any roads Based on client documentation, the minimum distance between an inverter and the nearest home will be 500 feet, the minimum distance between any solar panel and a public road will be 150 feet, and the minimum distance between any solar panel and a home that is not owned by a participant in the project will be 300 feet. The mid-level AC voltage from inverters is carried underground, which effectively suppresses EM radiation. Therefore, there should be no effects from EMI on FM reception.
Effects of Localized Reflections on FM Radio Reception
Obstructions such as mountains, hills, tall buildings, or similar high structures reflect VHF (both FM and VHF television) broadcast signals This “multipath” impact on FM reception can become significant when cancellation of desired signal occurs within the area of reception.
The effects of reflection are extremely local, likely occurring only within a short distance (200 feet or less) of the panels themselves. For listeners of the FM radio stations nearby, mitigation of signal distortion or loss to stationary receivers such as tabletop or portable radios is achieved by re-orienting the attached antenna on the receiver or moving the radio receiver slightly. Temporary, local, in-car, reception distortion may also be present, known as the “stop light effect,” where drivers listening to an FM station may lose the signal while sitting at a traffic signal, only to regain it when they move the vehicle 5-10 feet. The impaired FM signal will be regained as soon as the vehicle changes position.
Any short-term multipath impacts created by the solar panels on FM radio reception in motion will be short-lived and can be mitigated.
Television Broadcast Transmission Interference Study
Solar arrays located within two km of a transmitting TV facility (dashed red outline, Figure 6) have the potential to adversely affect TV transmissions.6 However, no transmitting TV facilities are located within two km of the study area (Table 4 and Figure 6). As a result, the proposed solar array should not create an adverse effect on the transmission of TV signals. The nearest television facility is Low Power TV station WAMS-LD, which is more than 32.1 km from the nearest PV array. Therefore, the Grange Solar Grazing Center will have no adverse effect on TV transmitter facilities.
Further, the possibility of a solar array interacting with near-field effects on an VHF and UHF television transmission is extremely remote since television transmitting antennas are typically elevated high above ground level to achieve maximum coverage It is improbable that a ground-based solar array would be within the main lobe pattern of a high-gain TV transmitting antenna in a way that interacts with the radiated pattern.
6 Two km is a conservative screening distance derived by rounding the Fraunhofer distance of 1,772 meters. The calculated distance of 1,772 meters is based on the largest off-the-shelf 36-element antenna on Channel 14 (the lowest TV channel in the UHF band).
Effects of Localized EMI on TV Reception
See the discussion in the FM section above for the potential effects of photovoltaic inverter EMI on FM Radio reception, which also applies to TV reception Based on client documentation, the minimum distance between an inverter and the nearest home will be 500 feet, the minimum distance between any solar panel and a public road will be 150 feet, and the minimum distance between any solar panel and a home that is not owned by a participant in the project will be 300 feet. The mid-level AC voltage from inverters is carried underground, which effectively suppresses EM radiation. Therefore, there should be no effects from EMI on TV reception.
Effects of Localized Reflection on TV Reception
Stationary or slow-moving PV arrays will have a negligible effect on nearby TV reception due to signal reflections. From a practical standpoint, the amount of signal that is reflected by these low-height PV panels is reduced significantly when they are installed on flat ground because they intercept and reflect less of the direct TV signal. For home television reception, aerial imagery shows that there are no homes within 200 feet of the proposed solar array. Further, any reflection-caused TV reception disruption is easily mitigated by either re-orienting the antenna on the receiver for fixed TVs or moving a portable device a few inches or feet.
Effects of Localized EMI on Land Mobile Base Stations
See the discussion in the FM and TV sections above for the potential effects of Photovoltaic Inverter EMI on FM Radio reception, which also applies to LMR reception, as LMR technology utilizes frequencies that are above the TV band that are smaller-wavelength and line-of-sight. There are four Land Mobile base stations whose licensed coordinates are shown within the study area (Table 5 and Figure 7). The closest land mobile base station is WNKN289, which is 88.8 meters (291 feet) from the nearest proposed PV array This exceeds the 150-foot recommended clearance distance, so there should be no localized EMI effects on land mobile base station transceivers.
Conclusion
Capitol Airspace conducted a communication systems interference analysis for the Grange Solar Grazing Center. This analysis assessed the potential for impact on various systems:
AM Radio
There are no AM transmission facilities within 6 km of the study area that would be affected by the proposed solar array. Further, the proposed solar project should not interfere with AM radio reception from an EMI standpoint, as the proposed solar array is far enough away from potential AM receivers as to not have an effect on AM reception However, should there be a complaint, a list of the 22 AM stations that serve the area is provided.
FM Radio
There are no FM transmission facilities within 1 km of the study area that would be affected by the proposed solar project Any EMI from the solar project would have a negligible impact on FM reception, and aerial imagery does not indicate the possibility of potential FM receivers within 150 meters of the proposed solar array. Any reflections that the solar project might produce to affect cellular reception are negligible due to the height difference between FM radio transmit antenna mounted on a tower and the PV arrays installed in the project. Further, they are temporary in nature and can be easily mitigated. As a result, FM radio reception should not be affected by the proposed project
Television
There are no TV transmission facilities within 2 km of the study area that would be affected by the proposed solar project. Any EMI from the solar project would have a negligible impact on TV reception, and aerial imagery does not indicate the possibility of potential FM receivers within 150 meters of the proposed solar array. Any reflections that the solar project might produce to affect TV reception are negligible due to the height difference between a TV transmit antenna mounted on a tower and the PV arrays installed in the project. As a result, TV reception should not be affected by the proposed project.
Mitigation options include simple changes to the placement of the receiving antenna or providing alternate means of viewing TV such as cable, satellite, or internet TV subscriptions.
Land Mobile Radio
There are four LMR base station license locations within 1 km of the project boundary (the actual location of one of the licenses is outside the boundary) and are located farther than 150 feet from any proposed PV arrays Any EMI from the solar project would have a negligible impact on LMR base stations, and aerial imagery does not indicate the possibility of potential LMR receivers within 150 feet of the proposed solar array. Any reflections that the solar project might produce to affect LMR reception are temporary in nature and can be easily mitigated. As a result, Land Mobile reception should not be affected by the proposed project.
In summary, the analysis indicates that the proposed Grange Solar Grazing Center is not expected to cause significant interference to nearby communication systems. Comprehensive evaluations of AM and FM Radio, TV, and Land Mobile Radio services suggest that any potential impacts can be managed through prudent mitigation strategies and awareness of the specific system dynamics. Further, based on client documentation, the minimum distance between an inverter and the nearest home will be 500 feet, the minimum distance between any solar panel and a public road will be 150 feet, and the minimum distance between any solar panel and a home that is not owned by a participant in the project will be 300 feet.
Based on the studies contained in this analysis, the Grange Solar Grazing Center should not cause any harmful effects to radio or television station transmission or reception, Land Mobile Radio reception or cellular/E911 service, either by EMI or by signal reflection, so long as the electrical components have been installed according to current codes and correct industrial installation procedures.
Further, as discussed in the analysis, if there are any effects on radio, television, land mobile, or cellular reception from the solar project, they are reasonably easily mitigated.
If you have any questions regarding the findings of this study, please contact James Scott or Cindy Cavell at (703) 256-2485.